The Tung Chung private doctor who dispensed at least five contaminated bottles of medicine containing up to 43 per cent of an alcohol disinfectant could face criminal prosecution, the Department of Health said last night. Director of Health Lam Ping-yan also called on private doctors to stop mixing medicine at their clinics as the practice could lead to dispensing blunders. Dr Lam said it had long been a practice among private doctors to dilute medicine to fit patients' needs. 'From the perspective of patient safety, we do not encourage this practice. It is vulnerable to human error,' Dr Lam said. His comments came after his department last week found private doctor Hin Lin-yee prescribed an antihistamine containing an isopropyl alcohol disinfectant to at least 31 children. The transparent syrup chlorpheniramine was prescribed to the children to treat runny noses and allergies. After the mix-up, Dr Hin temporarily closed his clinic at Yat Tung Shopping Centre. The department last night said it had tested 14 bottles of syrup submitted by 13 patients. Five bottles contained isopropyl alcohol, with concentrations ranging from 1.1 per cent to 43 per cent. A department spokesman said that in the five cases, the doctor was suspected to have supplied a drug 'unfit for use by man'. If convicted, he could be liable to a HK$50,000 fine and six months' jail. The 14 bottles of syrup were also found to contain chlorpheniramine, with concentrations ranging from 1.3mg/5ml to 8.8mg/5ml. Four bottles of chlorpheniramine not registered with the Health Department were seized from the clinic. Isopropyl alcohol was not detected in the seized syrup. Possession and sale of unregistered pharmaceutical products is an offence liable to a maximum penalty of a HK$100,000 fine and two years' jail. 'All evidence will be referred to the Department of Justice with a view to prosecution,' the spokesman said. Dr Lam said the mixing of medicines was still done at public hospitals and clinics, but professional dispensers and pharmacists were there to monitor the process. He said instead of diluting medicine for paediatric patients, doctors should provide a dispensing syringe for parents to use on their babies and toddlers. In another incident in May last year, 152 people with stomach ailments were given a mislabelled drug for diabetes by Wong Tai Sin doctor Ronald Li Sai-lai. Four people have since died. Medical Association president Choi Kin agreed that doctors should minimise the practice of diluting drugs at clinics.